The company issued a statement describing the possible industrial action, over pay and conditions, as "irresponsible", saying it could cost iron ore suppliers about $100 million a day.

The deckhands, who are members of the Maritime Union, have supported a ballot to take protected industrial action for up to a week at the Pilbara port if negotiations on a new enterprise bargaining agreement do not reach a resolution.

The ballot gives them 30 days to lawfully take action under the Fair Work provisions.

The workers would have to give Teekay Shipping three days notice of any stop work action.

Two other maritime unions, the marine engineers and maritime officers, are also considering strike action.

BHP said the state and federal governments also stand to lose royalty and tax revenue as a result of a strike.

Mining companies like BHP Billiton are not able to make up lost volume of this nature, and governments cannot recover these lost royalties and taxes.

BHP Billiton

"We estimate this will cost suppliers who ship out of Port Hedland around $100 million a day," the company said in a statement.

"Significant royalty and tax revenue will be lost to the Western Australian and federal governments.

"Mining companies like BHP Billiton are not able to make up lost volume of this nature, and governments cannot recover these lost royalties and taxes."

Fortescue Metals CEO Nev Power issued a statement saying the export of iron ore through Port Hedland was critical to the company, the mining industry and the Australian economy.

"There is a need to reform the outdated industrial laws that allow a handful of workers to hold to ransom the jobs of thousands of people, threaten state revenue, jeopardise the sustainability of local communities and damage our international trade reputation," he said.

Parties hopeful conciliation process will avoid strike action

BHP said the conciliation process is still progressing through the Fair Work Commission and they are hopeful the union and workers can reach an agreement.

Will Tracey from the Maritime Union said industrial action was considered a "last resort" and workers hoped to come to an agreement without striking.

He said the main issue of contention related to leave.

Tugboat workers work on a four-week on, four-week off roster and do not get annual leave.

"We are pursuing a claim of four weeks' leave a year," Mr Tracey said.

"We think this is very reasonable, given our members work 12 hours a day for 28 days straight in very tough conditions."

The union is also seeking a pay rise and said it had already agreed to a number of tradeoffs to secure its claims.

Mr Tracey said 100 per cent of the vote supported a 24-hour strike, and there was 98 per cent support for a 48-hour strike and a week-long strike.

"We've had a number of meetings but when the company continues to slide backwards on what we thought was a previously agreed position, workers have no other option but to go down that path," he said.

The two parties will appear before the Fair Work Commission again on May 20.